For about 6mo. or more now, I've been having this same problem with the voltage running through my car. It started when I'd notice all the light in my car randomly dimming/brightning as I would change throttle position. Later, I monitored the voltage readback on my GReddy timer as I would drive, and sure enough I'm getting very irregular voltage as I drive. It seems to work like this:

Off throttle, voltage jumps to about 12.8-13.2V, once I touch the throttle again, it dips to 11.8-12.0V, and just does this over and over as I am on/off the throttle. Somebody brought it to my attention that this *might* have a connection with my suck-*** idle since the Hondata unit is getting different votage readings from sensors over and over. The alternator was replaced maybe 6-8mo. after I bough the car under warranty when I noticed random dimming of the lights again (though to a much lesser level and completley independent of the throttle), does it make sense that perhaps the alternator is going bad again? Is there something esle that regulates current in the car that I might check? Any help would be apprieciated because this is driving me nuts!

 

*bump*

C'mon.. somebodys' gotta have an idea..

 

Damn I'm taking a class on basic electronics so I'm not a pro. By it (lights) flickering it sounds as though its a bad connection. i would check what all lights dim in the car and find what wires/wire they run off of then check the ground there. Do you have access to a voltameter? Anyone else have any ideas?

 

Check all grounds and make sure they are good.
Once you have done that and you still have an issue. Look at the voltage regulator or the alternator.

All those extra goodies might be too much for the stock alt.

 

Where's the voltage regulator?

 

brand new alternator or a rebuilt one from like Autozone or someplace?

wouldn't hurt to take the alternator to Autozone and have them check it. Do the lights dim when you do anything else? like air conditioner, radio (turning volume up, assuming you have an amp in the back), window rolling up/down....etc..

 

Nope, they don't dim for any obvious use of power like windows, sunroof or anything esle, just that wierd random voltage glitch and I can't figure out why?

Alternator was repalced by Honda so I'd assume with an OEM unit.

 

this has never happened in my civic, but it did happen in my pontiac and it turned out to be the alternator. but i noticed it for the first time one day and later that day it was completely dead. so if this has been happening for 6 months, got me

 

Most car dealerships sell rebuilt alternators, but its no big deal. It sounds like a bad connection or you are getting a lot of resistance in your wires somehow.